Furnace charging apparatus



Sept. 10, 1963 F. KOCKS FURNACE CHARGING APPARATUS 2 Sheets-Sheet 1 Filed June 5. 1961 Sept. 10, 1963 F. KOCKS FURNACE CHARGING APPARATUS 2 Sheets-Sheet 2 Filed June 5. 1961 m 2 m H 5 T m a i A a. w V; 5 m0 a/J W V H V 7 A 7 Unite States 3,103,286 FURNACE CHARGING APPARATUS Friedrich Kocks, Berliner Allee 48, Dusseldorf, Germany The present invention relates to apparatus for the production of steel and, more particularly, to a furnacechar-ging device.

Open-hearth furnaces, in particular Siemens-Martin furnaces, are charged at the present time by means of box-like troughs; the troughs are loaded with scrap .at the site of the scrap or in front of the furnace, carried by the rotatable member of a charging crane, introduced into the furnace and the contents discharged by tipping them into the furnace. The dimensions of the troughs are determined by the form of the furnace door openings and by the means by which the troughs are transported from the site of the scrap or the furnace staging to the furnace. The capacity of the trough varies between 0.8 to 1.8 cubic meters. The bulk weight of the loose scrap varies between 700 and 800 kg. per cubic meter, and therefore the weight of the contents of a trough varies between 560 and 1400 kg. From these figures it will be seen with the usual charging of the Siemens-Martin furnace having a capacity of about 150 tons its doors must be opened and closed about 200 times. It is an object of the invention to provide an improved charging device adapted to obviate this disadvantage.

It is, therefore, proposed in accordance with the invention, when charging a Siemens-Martin furnace (particularly one which is operated as a pre-melting furnace for a subsequent finishing furnace) to use, instead of the customary charging troughs, so-called charging plates, the length of which approximately corresponds to the full width of the furnace and the width of which is more than double the width of the troughs commonly in use. A charging plate which is 4 meters in length and 2 meters in breadth can take a charge of about 3 to 4 tons of scrap with an average bulk height of 0.5 meters and with scrap of the usual bulk weight. This is a capacity which is about three times :as great as, that of the custornary charging troughs hitherto used for charging Siemens-Martin furnaces. The charging plates used in accordance with the invention can deliver their charge by simply inclining them sideways and allowing the charge to slide down into the furnace. In order to charge the furnace uniformly, the charging plate is inclined alternately to one side and to the opposite side. Two such charging plates are sufiicient for charging large furnaces which then need be provided with only two doors. In the customary Siemens-Martin furnace, in order to ensure a uniform deposit on the surface of the hearth, five of such doors are provided. When the ch-arging plates in accordance with the invention are used they introduce into the furnace about three times of the amount discharged by the troughs common heretofore and therefore have the further important advantage that the frequency with which the doors of the furnace must be opened and closed for charging is reduced to about onethird. This leads to a corresponding reduction in heat losses and an increase in the economy of the operation of the furnace.

The plates used for charging the furnace are connected to rotatable members of the charging machines which can travel on rails running at right angles to the axis of the furnace to the front of each door of the furnace. After being discharged they move on these rails to the site of the scrap or to another suitable charging site. The charging of the plates can be facilitated by loading them from bunker-like vessels provided with guide plates and the inclined sideways in the furnace. The movement of the side walls can be effected mechanically, electrically or by other means. I

A charging device according to the invention, is illustrated, by way of example, in the accompanying drawings in which:

FIGURE 1 is a side elevation partly in cross-section of a Siemens-Martin furnace for melting .a preliminary metal together with the machine for changing it;

FIGURE 2 is a plan partly in section of the installation shown in FIGURE 1;

FIGURE 3 is a side elevation of a charging machine which runs on rails;

FIGURE 4 is a plan of the charging machine shown in FIGURE 3, and

FIGURE 5 is a diagrammatic section on the line V-V of FIGURE 4.

Referring to the drawing, the preliminary melting furnace 1, which is an ordinary Siemens-Martin furnace, produces continuously, from a charge consisting mainly of scrap, a preliminary metal which has a maximum content of 1.5% of carbon and is delivered in batches to finishing furnaces, which are not illustrated, but may be Siemens-Martin or electric furnaces. By the sub-division of the two tasks to be carried out by the furnaces, that is to say by the preliminary melting and the finishing furnace, a great economy in the production of steel in the open-health method is effected.

The charging of the preliminary melting Siemens- Martin furnace must be adapted to suit the altered method of operation which merely consists in continuous melting of the charge. In the furnace indicated in the drawing, charging is effected by two charging machines 2 and 2 which can travel on rails 4 at right angles to the axis of the furnace 1.

Instead of the usual charging trough, .a charging plate 6 (FIG. 3) is detachably connected to a rotatable member 5. of the charging machine. The length'of the plate 6 is about equal to the width of the furnace and its width is of the order of two meters. The weight of the charge on such a charging plate is several times that of the charge carried by the usual charging troughs. I

In order to increase still further the capacity of the charging plates, side walls can be hinged to the plates. A charging plate of this kind is illustrated FIGURES 4 and 5.

The side walls 8 and 9 are hinged to the charging plate 6 by pivots 7 and their movement when the plate is inclined is controlled by links 10 and 11. One end of each link is'pivoted to the free end of the side Walls 8, 9 and the other endis similarly pivoted to a fixed shield plate 12 for the rotatable member 5. The latter is journaled in a pair of bearings 13, 18 upon uprights 17, 20 of the carriage 2 and rotated via a pinion 16 and a driven gear 15 by a motor 14. When the charging plate is brought into the inclined position illustrated in broken lines in FIGURE 5 by motor 14, the link 11 causes the side wall 9 to swing downwardly and the link 10 pulls the side wall 8 inwardly. In the opposite inclined position of the plate 6, the side wall 8 swings downwardly, whereas the wall 9 is pulled inwardly. A motor 19 drives a shaft 22 whose gears rotate the wheels 21 to shift the carriage 2 toward and away [from the furnace.

It will be seen from FIGURE 2 that the furnace 1 need 3 only be provided with two ports 3 when the charging machine of the invention is used. This leads to a considerable improvement in the heat economy of the furnace.

The charging device described for use with a Siemens- Martin furnace operating as a preliminary melting furnace, has advantages not only for this purpose but also for a Siemens-Martin furnace which is operated in the usual manner, its charging being considerably shortened. Attempts have previously been made to obtain the same results with other means, for example by increasing the bulk Weight of the scrap, by cutting it into short pieces and sorting it. Also packaging presses have been constructed which convert entire motor cars into small packages and bring the scrap into a very compact form. It has been found by experience, however, that packets of scrap of this kind only melt slowly in a Siemens-Martin furnace, because the flames only have access to their outer surface. Therefiore, this has been given up and scrap which has been pack-aged for transport purposes has been cut into small pieces or even torn apart again before being charged into the Siemens-Martin furnace. In any case, the preparation of scrap for the charge of an open-hearth furnace, no matter Whether it is effected by packaging, cutting the package up again, or simply by merely tearing it apart is very expensive. When the charging device of the invention is used, such methods can be omitted, because any sort of scrap can be transported on the large charging plates and can be introduced into the furnace simply by tilting the plates.

I claim:

1. In a steel-making plant provided with an open-hearth furnace having an elongated furnace chamber and a longitudinal wall provided with at least one throughgoing aperture opening into said chamber, the combination therewith of a furnace-charging device, said device comprising:

guide rail means extending transversely to said wall;

a carriage displaceable on said guide-rail means toward and away from said furnace;

Ia shaft journaled on said carriage for rotation about an axis transverse to said wall and having an extremity extending irom said carriage in the direction of said wall while being aligned with said opening;

a substantially flat charging plate rigid with said extremity and swingable therewith between a normal position whereby said plate is substantially horizontal and at least one off-normal position wherein said plate is angularly offset from the horizontal about said axis, said plate having a pair of opposite lateral edges extending parallel to said axis, said plate being formed with :a pair of respective retaining wall members along said lateral edges, at least one of said edges swinging downwardly upon angular displacement of said plate between said normal and offnormal positions;

pivot means along said one edge articulatel-y connecting the respective one of said members to said plate for swinging movement about a pivotal axis parallel to the axis of rotation of said shaft;

link means articulated to said carriage and tosaid one member for swinging same downwardly upon rota- 4 tion of said plate into said off-normal position whereby material carried by said plate may be discharged along the corresponding edge;

first drive means on said carriage for displacing said carriage along said guide rail means into a position wherein said plate extends through said opening into said chamber; and

second drive means for rotating said shaft about said axis between said normal and off-normal positions of said plate in said position of said carriage.

2. In a steel-making plant provided with an openhealrth furnace having an elongated furnace chamber and a longitudinal wall provided with at least one throughgoing aperture opening into said chamber, the combination therewith of a furnace-charging device, said device comprising:

guiderail means extending transversely to said Wall;

a carriage displaceable on said guide-rail means toward and away from said furnace;

a shaft journaled on said carriage for rotation about an axis transverse to said wall and having an extremity extending from said carriage in the direction of said wall while being aligned with said opening;

a substantially flat charging plate rigid with said extremity swingable therewith between a normal position wherein said plate is substantially horizontal and at least one off-normal position wherein said plate is angularly offset firom the horizontal about said axis, said plate having a pair of opposite lateral edges extending parallel to said axis, said plate being formed with a pair of respective retaining wall members along said lateral edges, at least one of said edge swinging downwardly upon angular displacement of said plate between said normal and offnormal position;

pivot means along said one edge articulately connecting the respective one of said members to said plate for swinging movement about a pivotal axis parallel to the axis of rotation of said shaft;

link means articulated to said carriage and to said one member for swinging same downwardly upon rota- :tion of said plate into said oil-normal position whereby material carried by said plate may be discharged along the corresponding edge;

firs-t drive means on said carriage for displacing said carriage along said guide-rail means into a position wherein said plate extends through said opening into said chamber, said plate extending in the direction of said axis over a major fraction of the transverse width of said chamber; and

second drive means for rotating said shaft about said axis between said normal and elf-normal positions of said plate in said position of said carriage.

References Cited in the file of this patent UNITED STATES PATENTS 

1. IN A STEEL-MAKING PLANT PROVIDED WITH AN OPEN-HEARTH FURNACE HAVING AN ELONGATED FURNACE CHAMBER AND A LONGITUDINAL WALL PROVIDED WITH AT LEAST ONE THROUGHGOING APERTURE OPENING INTO SAID CHAMBER, THE COMBINATION THEREWITH OF A FURNACE-CHARGING DEVICE, SAID DEVICE COMPRISING: GUIDE-RAIL MEANS EXTENDING TRANSVERSELY TO SAID WALL; A CARRIAGE DISPLACEABLE ON SAID GUIDE-RAIL MEANS TOWARD AND AWAY FROM SAID FURNANCE; A SHAFT JOURNALED ON SAID CARRIAGE FOR ROTATION ABOUT AN AXIS TRANSVERSE TO SAID WALL AND HAVING AN EXTREMITY EXTENDING FROM SAID CARRIAGE IN THE DIRECTION OF SAID WALL WHILE BEING ALIGNED WITH SAID OPENING; A SUBSTANTIALLY FLAT CHARGING PLATE RIGID WITH SAID EXTREMITY AND SWINGABLE THEREWITH BETWEEN A NORMAL POSITION WHEREBY SAID PLATE IS SUBSTANTIALLY HORIZONTAL AND AT LEAST ONE OFF-NORMAL POSITION WHEREIN SAID PLATE IS ANGULARLY OFFSET FROM THE HORIZONTAL ABOUT SAID AXIS, SAID PLATE HAVING A PAIR OF OPPOSITE LATERAL EDGES EXTENDING PARALLEL TO SAID AXIS, SAID PLATE BEING FORMED WITH A PAIR OF RESPECTIVE RETAINING WALL MEMBERS ALONG SAID LATERAL EDGES, AT LEAST ONE OF SAID EDGES SWINGING DOWNWARDLY UPON ANGULAR DISPLACEMENT OF SAID PLATE BETWEEN SAID NORMAL AND OFFNORMAL POSITIONS; PIVOT MEANS ALONG SAID ONE EDGE ARTICULATELY CONNECTING THE RESPECTIVE ONE OF SAID MEMBERS TO SAID PLATE FOR SWINGING MOVEMENT ABOUT A PIVOTAL AXIS PARALLEL TO THE AXIS OF ROTATION OF SAID SHAFT; LINK MEANS ARTICULATED TO SAID CARRIAGE AND TO SAID ONE MEMBER FOR SWINGING SAME DOWNWARDLY UPON ROTATION OF SAID PLATE INTO SAID OFF-NORMAL POSITION WHEREBY MATERIAL CARRIED BY SAID PLATE MAY BE DISCHARGED ALONG THE CORRESPONDING EDGE; FIRST DRIVE MEANS ON SAID CARRIAGE FOR DISPLACING SAID CARRIAGE ALONG SAID GUIDE RAIL MEANS INTO A POSITION WHEREIN SAID PLATE EXTENDS THROUGH SAID OPENING INTO SAID CHAMBER; AND SECOND DRIVE MEANS FOR ROTATING SAID SHAFT ABOUT SAID AXIS BETWEEN SAID NORMAL AND OFF-NORMAL POSITIONS OF SAID PLATE IN SAID POSITION OF SAID CARRIAGE. 